21124114681 has 4 divisors (see below), whose sum is σ = 21137343652. Its totient is φ = 21110885712.

The previous prime is 21124114607. The next prime is 21124114691. The reversal of 21124114681 is 18641142112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8727296400 + 12396818281 = 93420^2 + 111341^2 .

It is a cyclic number.

It is not a de Polignac number, because 21124114681 - 2⁷ = 21124114553 is a prime.

It is a super-2 number, since 2×21124114681² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124114691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6612090 + ... + 6615283.

It is an arithmetic number, because the mean of its divisors is an integer number (5284335913).

Almost surely, 2^21124114681 is an apocalyptic number.

It is an amenable number.

21124114681 is a deficient number, since it is larger than the sum of its proper divisors (13228971).

21124114681 is a wasteful number, since it uses less digits than its factorization.

21124114681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13228970.

The product of its digits is 3072, while the sum is 31.

Adding to 21124114681 its reverse (18641142112), we get a palindrome (39765256793).

The spelling of 21124114681 in words is "twenty-one billion, one hundred twenty-four million, one hundred fourteen thousand, six hundred eighty-one".